This invention relates to apparatus for replacing rotating mandrels on which paper, fabric or other web is wound in a process of applying the web to, or removing it from, a succession of the mandrels. The invention is illustrated and described as applied to a winder, in which the web is wound onto the mandrels to be replaced.
Typically such winding may be for the purpose of continuously rewinding a succession of mill rolls of the web into smaller rolls for use by the consumer, or to rewind a web after it has passed through web processing machinery.
When successive rolls are to be wound it is desirable to be able, automatically and without interrupting the winding, to sever the web from a fully wound roll and adhere the severed end to a new mandrel. To avoid a shock on the web when it adheres to the new mandrel, the mandrel should already be rotating at a surface speed equal to the web speed. It is also desirable in such winding apparatus to transfer mandrels between stations, e.g., in a winder, between loading, splicing, winding and unloading stations.
Two types of mandrel drive systems are in common use: center drives which rotate the mandrel at a controlled angular speed; and surface drives, which directly engage the surface of the core-supporting mandrel, or even the web itself as it winds onto the mandrel, providing direct control over surface speed. To maintain constant surface speed, center drives automatically slow angular speed as the diameter of the roll being wound grows in diameter. Conventional center drive winders employ costly and complex turret arrangements to accomplish automatic splicing of new mandrels.